Merge branch 'jk/match-pathname-fix'

The wildmatch code had a corner case bug that mistakenly makes
"foo**/bar" match with "foobar", which has been corrected.

* jk/match-pathname-fix:
  match_pathname(): give fnmatch one char of prefix context
  match_pathname(): reorder prefix-match check

dir.c

@@ -1388,18 +1388,25 @@ int match_pathname(const char *pathname, int pathlen,
 
 		if (fspathncmp(pattern, name, prefix))
 			return 0;
-		pattern += prefix;
-		patternlen -= prefix;
-		name    += prefix;
-		namelen -= prefix;
 
 		/*
 		 * If the whole pattern did not have a wildcard,
 		 * then our prefix match is all we need; we
 		 * do not need to call fnmatch at all.
 		 */
-		if (!patternlen && !namelen)
+		if (patternlen == prefix && namelen == prefix)
 			return 1;
+
+		/*
+		 * Retain one character of the prefix to
+		 * pass to fnmatch, which lets it distinguish
+		 * the start of a directory component correctly.
+		 */
+		prefix--;
+		pattern += prefix;
+		patternlen -= prefix;
+		name    += prefix;
+		namelen -= prefix;
 	}
 
 	return fnmatch_icase_mem(pattern, patternlen,

t/t0008-ignores.sh

@@ -847,6 +847,17 @@ test_expect_success 'directories and ** matches' '
 	test_cmp expect actual
 '
 
+test_expect_success '** not confused by matching leading prefix' '
+	cat >.gitignore <<-\EOF &&
+	foo**/bar
+	EOF
+	git check-ignore foobar foo/bar >actual &&
+	cat >expect <<-\EOF &&
+	foo/bar
+	EOF
+	test_cmp expect actual
+'
+
 ############################################################################
 #
 # test whitespace handling